Picture frame



FIG. 1 is a perspective view of a picture frame, showing my new design; the broken line showing of a sheet retained in the arc is for environmental purposes only and forms no part of the claimed design;

FIG. 2 is a front side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a side right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a front elevational view of an alternative embodiment of my picture frame having a flush top line on the base, the base is the rear view being a mirror image thereof; and,

FIG. 9 is a right side elevational view of my alternative embodiment, the base in the left side view being a mirror image thereof. 

The ornamental design for a picture frame, as shown and described. 